Forced air flow warm air heating furnace



y 27, 1954 J. P. GLASBY, JR 2,684,667

FORCED AIR FLOW WARM AIR HEATING FURNACE Filed June 26. 1948 6Sheets-Sheet 1 IN V EN TOR. (/ONA THAN R 62 A55); (/19,

ATTORA/EX July 27, 1954 J. P. GLASBY, JR

FORCED AIR FLOW WARM AIR HEATING FURNACE Filed June 26. 1948 6Sheets-Sheet 2 A "C M Y d B A 7' TOR/VEX y 1954 J. P. GLASBY, JR2,684,667

FORCED AIR FLOW WARM AIR HEATING FURNACE Filed June 26. 1948 6Sheets-Sheet 5 l A m M A W I47 146 144 v INVEN TOR.

l/ONA THAN/D. 62 A55); JR.)

A 7' TORNFY y 1954 J. P. GLASBY, JR 2,684,667

FORCED AIR FLOW WARM AIR HEATING FURNACE Filed June 26. 1948 I 6Sheets-Sheet 4 JNVENTOR. 3 l/O/VA THAN/3. 62 A55); UR.)

A 7'7'ORNEX J.- P. GL-ASBY, JR 2,684,667

FORCED AIR FLOW WARM AIR HEATING FURNACE v 6 Sheets-Sheet 5 w 4 w 5 W 3L l/J 4 5 N5 m M 9 m 4 .4 m 7 w M 4 w 5 0 M 7 1 7 1 8 d m 9 m 5 w 7 l AN g 1 1 N4 w a 4 ah- N a J m A, c. fmv N \1 A v w H 91% l L j l w x m 6-1 A July 27, 1954 Filed June 26. 1948 ATTO/P/VEX July 27, 1954 .1. P.GLASBY, JR

FORCED AIR FLOW WARM AIR HEATING FURNACE Filed June 26. 1948 6Sheets-Sheet 6 INVENTOR. (/ONATI/A/VYID. 62 A 55); (49., BY

A 7 TOR/V5)? Patented July 27, 1954 UNITED AENT OFHCE FORCED AIR FLOWWARM AIR HEATING FURNACE Application June 26, 1948, Serial No. 35,441

Claims.

The present invention relates to heating devices and particularly to ablower type air heater or warm air furnace having a downwardly directedwarm air outlet.

An air heater in accordance with the invention is particularly suitablefor use in heating cellarless buildings. In such buildings the spacebeneath the building is generally small and inaccessible and thus isunsatisfactory for the installation of an air heating device.Accordingly the device is often installed above the level of the floorso as to be accessible. It is thus important that the device berelatively small and present a pleasing appearance, and further, thatthe heater have an efiicient distribution of heating surface in order toadd to its economy. Prior devices have, in many instances, beenconstructed so that the heater pipes have extended outwardly from theupper portion thereof resulting in excessively Warm ceilings and coldfloors.

Other devices have had the heating pipes brought from the top of theheater down along the sides thereof to an under floor distributioncenter. While such units have provided a better heat distribution theyhave been often unsightly because of the downwardly directed pipes,which also are objectionable as they require considerable fioor area.Another disadvantage is that the downwardly directed heater pipes loseconsiderable heat by radiation necessitating expensive and generallyunsightly insulation.

The present invention aims to provide an air heater of improvedconstruction which overcomes the foregoing difficulties anddisadvantages.

Another object of the invention is to provide an air heater or warm airfurnace which is simple and economical in manufacture, efficient inoperation and durable in use.

In accordance with the invention the foregoing objects are accomplishedby providing an air heater which is adapted to be placed on the floorlevel or above the ceiling of a building to be heated. The heater ismade with a warm air blower having a downwardly directed warm airoutlet. The construction of the heater is such that'the blower and itsoutlet are positioned in the hottest part thereof and are almostcompletely surrounded by the hot combustion gases. An inner shellconfines the combustion gases against the outer walls of the blower andits outlet. The cold air to be heated in turn almost completelysurrounds the inner shell, the air thus being preheated before enteringthe blower and also acting as an insulating medium so that practicallyno heat is lost from the walls or top 2 of the heater. The plenum ispositioned under the heater and thus completes the insulation thereof.More specifically the blower is located so as to form the roof of thecombustion chamber while the downwardly directed blower outlet forms onewall of the combustion chamber. By means of the inner shell the hotcombustion gases are directed over the top of the blower casing anddownwardly along its sides thence upwardly against the inner surface ofthe shell and upwardly out the outlet, thus the combustion gasespractically completely surround theblower casing. The air to be heatedis directed over practically the entire outer surface of the shell andinto the blower, thus becoming preheated before entering the blower andacting as an insulating medium to prevent heat from escaping into thespace in which the heater is located. Another feature of the air heateris its construction permitting the blower and its motor to be removedfrom the front thereof as a unitary assembly without access being had tothe sides or rear thereof. Likewise, the heating unit may be easilyinserted or removed from the front of the heater.

The heater in accordance with the invention is advantageous in that itmay be placed in corners or in available cupboard space or the like yetits moving parts are readily accessible from the front for servicing orrepairs. minimum of floor space is occupied by reason of its compactconstruction which is easily adapted to a pleasing design. The heater isadapted to use a heating unit burning gas, oil or other suitable, fuelswithout expensive alterationsin its construction. By reason of itsextended flue travel the flue gases are discharged from the heater at alow temperature resulting in a very eflicient unit.

Other objects and advantages of the invention will be apparent from thefollowing description and from the accompanying drawings which show, byway of example, an embodiment of the invention.

In the drawings.

Figure 1 is a front elevation of a warm air furnace in accordance withthe invention with decorative front wall removed. Certain of theinterior partitions are shown in dotted lines.

Figure 2 is a front vertical sectional view of the warm air furnacetaken along the lines 22- of Figures 4 and 5, the path of the combustiongases being shown by the use of arrows.

Figure 3 is a view corresponding to Figure 2 taken along the lines 3-3of Figures 4 and 5, the

3 paths of the air to be heated outside of the blower being shown byfull arrows, while the air in the blower casing is shown by dottedarrows.

Figure 4 is a central vertical sectional view of the furnace taken alongthe line 4-4 of Figure 5.

Figure 5 is a horizontal sectional view of the furnace takenapproximately along the lines 5-5 of Figures 2 and 3.

Figure 6 is a plan view of the plenum positioned under the furnace.

Figure '7 is a side view at an enlarged scale of the detachable blowerassembly.

Figure 8 is an end view corresponding to Figure '7.

Referring to the drawings there is shown an air heating device or warmair furnace ID in accordance with the invention. The heater includes ahousing ll having therein a heat exchanger including a fire box orcombustion chamber l2. The roof of the fire box is formed by an involutesurface it of a blower casing it. One of the side walls of thecombustion chamber is formed by inner wall 56 of the downwardly directedoutlet I? of the blower casing. The other walls of the fire box areformed by an inner shell !9 enclosing the blower casing 15 andseparating combustion gases and air to be heated. A blower fan 28 ispositioned in the blower casing !5 to expel the warmed air downwardlyinto a plenum 2i positioned under base 22 of the heater for thedistribution of the warmed air throughout a building or other space.

The combustion chamber I2 is adapted to receive any conventional heatingunit 23 adapted to burn oil, gas, or other suitable fuel. The walls ofthe combustion chamber are formed of any appropriate material, such assheet steel, adapted to separate the combustion gases from the air to beheated and to provide efficient heat transmission therebetween. Theinner shell I9 is made in any conventional manner such as by attachingsheet metal partitions together by welding or other suitable means.

As may be seen in Figure 2, a vertically extending partition 25 formsone wall of the shell 19 and is spaced from the involute surface Hi ofthe blower casing to define combustion gas passage 26, and spaced fromside wall 21 of the housing H to define an air passage 29. end 30 of thepartition 25 is terminated a predetermined distance below the innersurface of top 3! of the housing H. A horizontally extending partition32 is positioned above the involute surface 14, one end 36 thereofmeeting upper end as of the vertically extending partition 25. Thepartition 32 is spaced from the involute surface it to define combustiongas passage 34, and spaced below the inner surface of the housing top 3!to form an air passage 35. A second vertically extending partition 39 isspaced between side wall A of the housing I I and outer wall 42 of theblower outlet i! to form a combustion gas passage 44 with the blowerwall 42, and to form an air passage 45 with the housing wall 50. Upperend 4t of the partition 39 abuts against end ll of the horizontallyextending partition 32. A baffle or partition 49 has its lower end tattached to the blower outlet wall 42, its upper end 53 being turnedinwardly and abutting against the under surface of end 41 of thepartition 32. The width of the baffle 49 is greater than the width ofthe blower wall 42 so that the baffle will abut against front and rearwalls to be later described and its length Upper is such as to providecombustion gas passages 5| between its lower edge and the base 22. Thebaflle upper end 53 is apertured as indicated at 54 to vent thecombustion gas passage 34 as will hereinafter appear.

The enclosure of the shell l9 forming the combustion chamber [2 iscompleted by a floor 55 and by front and rear walls or partitions 56 and57 (Fig. 4). Both of the walls 56 and 5'! extend upwardly to meet theedges of the horizontally extending partition 32 and both formed withopenings to provide blower casing inlets 58 and 55! The inlet openingsare made of a size to permit the insertion of the blower fan 28. A doorSB (Fig. 1) is made in the front combustion chamber wall 55 and may beformed with an opening 6| providing a passage for air to support thefuel combustion and for a fuel pipe (not shown). A transparent window E2is placed in the door 68 in order that the flame may be viewed from thefront of the heater. A cleanout door 64 may also be made in the frontwall 55.

The front and rear inner shell walls 5t and iii are spaced from thesides of the blower outlet ll, to provide combustion gas passages 66 and6": which are blocked off from the blower inlets 53 and 5?; bycylindrically shaped barriers 8t and lb, abutting on their inner endsagainst blower walls H and .2 about openings therein for the inlets 58and 59, and abutting on their outer ends against the walls 56 and Elabout the blower inlet openings therein. The front and rear inner shellwalls 56 and 51 are spaced from front and rear housing walls is and "iiito provide air passage spaces EE and H. In order that the air en teringthe blower inlets 53 and 59 will be forced to pass over the outer wal;sof the shell [9 to be preheated before entering the blower, generallyU-shaped partitions or barriers is and 3B are interposed, respectively,between the housing walls it and i5, and the inner shell walls 58 and5'1, with the legs of the barriers turned upwardly and terminatingapproximately at the upper corners of the inner shell ii). The bottomsof the U-shaped members it and 89 extend slightly below the blowerinlets 5i; and 53, the air passages formed by the upwardly turnedmembers it and as being indicated by E! and 82.

A combustion gas outlet or stack at is provided extending through anaperture in the top housing wall 3| and through an aperture 35 in thehorizontally extending inner shell partition 32. The inwardly turnedupper en 53 of the barrier 69 provides clearance for the combustiongases to pass from the combustion gas passage i l through the outlet 84.

In order that the combustion gases in the combustion chamber it will bedistributed against the various surfaces of the blower casing l5 and itsoutlet ii, an adjustable barrier 53;] is placed on the combustionchamber and includes a supporting hollow member 9% attached at its upperend to the underside of the involute blower surface 54. A lowersupporting member t2 is adapted to into the lower end of the uppersupporting member $3! and may be adjustabiy positioned by a pin esextending through a plurality of aligned apertures in the supportingmembers 9i and fit. A bailie plate of any desired configuration isattached to the lower end of the supporting member 92 in any suitablemanner such as by a bolt 96.

A detachable blower assembly its is adapted to be positioned so as to beremovable from the front of the heater it. A frame Hli carries on itsupper surface a motor mounting arm I02 supporting a motor I04 throughvibration resisting mountings H and W6. On the lower surface of theframe iili are carried bearing members Hi9 and i it through vibrationresisting members ii i and i ii. A blower shaft H4 is journalled in thebearing members i653 and lit and carries a driven pulley H5 at its outerend and the blower fan it at its inner end. The driven pulley is rotatedby a belt H6 engaging with a driving pulley i ii carried by motor shaftM8.

The front housing wall it is formed with an opening H9 adapted toreceive the blower fan 20. A cover plate H to cover the opening H9 issecured to the end of the frame Nil and apertured to receive the blowershaft lid. The cover plate I29 is apertured to receive bolts havingtheir inner ends E22 secured to the front shell wall 56, nuts I23 engagethe ends of the bolts to secure the blower assembly in position. Ablower funnel E28 is attached to the cover plate I26 by tubular membersI in a welded assembly. A blower funnel 421 corresponding to the blowerfunnel IE6 is attached to the rear shell wall 51 about the blower inlet58.

A tubular member lie is positioned in an opening in the lower end of thehousing wall i i to provide an air passage from the front of the heaterthrough the door 69 to the combustion chamber iii.

The heater ill has attached connecting members or straps 329 adapted tobe received in an angle iron frame 39 which may be attached to the noorof the building. The housing walls 2'5, 40, id and "it (Fig. 4) areeasily attached to the edge of the angle iron frame E38 in any suitablemanner, such as by clips Hill. The housing top 3! has a flanged edge Hi2adapted to overlie the top ends of the walls 21 and 38, while the walls7 3 and 35 have flanged edges I3 1 adapted to engage with the top 3|.Screws, bolts, or other conventional means may be used to hold the wallsin position. A front cover E35 with flanged openings I35 is provided tocover the blower motor and burner assembly, the air for the combustionchamber i2 entering through the flanged openings H6. The outer walls 21,ill, it, 75 and the top 35 of the outer housing H may be made of anysuitable material such as sheet metal, and may be made with doublewalls, either with or without insulating material therebetween.

The plenum 2i is positioned under the base 22 of the heater and ispreferably of rectangular shape with front and rear walls Hill and MI,and with side walls M2 and 43. The plenum bottom M4 is closed. Apartition M5 divides the plenum into a warm air compartment ME and acold air or return air compartment Ml. The warm air compartment hill isclosed by a top Hi9 having an opening I50 to receive the end of thedownwardly directed blower outlet ll. ihe top of the cold aircompartment is open to permit the cold'air to flow upwardly over theplenum top M9 which is spaced below the heater bottom providing an airpassage i5i so that the air may flow into the various air passages aboutthe shell Hi. The plenum walls are apertured to receive fittings I52adapted to connect with the warm air conduits of the building. A coldair fitting H53 is adapted to be connected to cold air conduitsreturning air from the building. The upper edges of the plenum walls areflanged as indicated at I55 to engage with the angle iron frame i3il forthe support of the plenum.

The path of the combustion gases is shown in Figures 2, 4 and 5. The airto support combustion enters the heater through the flanged openings 836and the tubular member I23 into the combustion chamber [2 through itsdoor 69. As may be seen in Figure 2 the combustion gases flow upwardlythrough the combustion gas passages 26 and 34 over the top of the blowercasing 15, then are directed towards the sides and downwardly by thebaffle 53 along the sides of the blower outlet I! in the combustion gaspassages 63 and 5'! (Figure 5), around the baflie lower ends 50, in thecombustion gas passages 55!, thence upwardly through the combustion gaspassage M and out of the heater through the stack 8%. The aperture 5 3being provided to vent the combustion gas passage 3 from any leakage ofgas from the heating unit 23 while the heater is not being operated. Thecombustion gases thus have an extended flue travel practicallycompletely covering the outer surface of the blower casing I5, itsoutlet ii, and the inner surface of the shell 19.

The path of the air to be heated is shown in Figures 3, 4 and 5. The airenters through the opening I53 to the cold air compartment l4! of theplenum 2i and is drawn upwardly and across through the air passage I51and upwardly through the air passages 28, 25, 16 and l"! (between allfour outer sides of the inner shell I9 and the inner walls of thehousing H), over the top 32 of the inner shell I9, and downwardly intothe air passages 3i and 82 into the blower inlets 55 and 59. The air hasalready been preheated by its contact with the outer surfaces. of theinner shell i 9 and is further heated inside the blower casing 15. Theair is expelled through the blower outlet H by the blower fan 28, and isstill further heated as it passes through the blower outlet I! into thewarm air compartment I46 of the plenum 2!. The warmed air is thusfinally heated the hottest part of the heater and discharged therefromwithout loss of heat.

It is thus apparent that an air heating device or warm air furnace hasbeen provided which is efficient, compact and adaptable for rugged'use.The heater may be placed on the floor of a building or in the atticspace over the ceiling. The unit radiates practically no heat throughits walls and thus may be placed adjacent the building walls withoutdanger of overheating the walls and causing fire. The heater is readilyserviceable from the front thereof and thus is particularly adaptablefor use in small spaces such as cupboards or the like.

While the invention has been described and illustrated with reference toa specific embodiment thereof, it will be understood that otherembodiments may be resorted to without departing from the invention. Forexample, while the inner shell 59 has been described as beingrectangular it might equally well be made circular in shape. Likewise,the position of the stack 84 is shown as at the top of the heater, whileobviously, it might alternatively be placed. on the upper sides of theheater. Likewise, various shapes of blower casings might alternativelybe used. Therefore, the form of the invention set out above should beconsidered as illustrative and not as limiting the scope of thefollowing claims.

I claim:

1. In an air heating device, a housing, a combustion gas outlet adjacentthe top of the housing, a blower casing positioned within the housingand having an inlet, a warm air blower in the blower casing, the blowercasing including an involute surface about the periphery of the blowerand a downwardly directed warm air blower outlet, a first verticallyextending partition positioned between one end wall of the housing andthe involute surface of the blower casing and spaced therebetween, ahorizontally extending partition having one end meeting the upper end ofthe first vertical partition and spaced between the top wall of thehousing and the top or" the blower casing, a second vertically extendingpartition at its upper end meeting the other end of the horizontallyextending partition and at its lower end meeting the bottom of thehousing and spaced between the other end wall of the housing and theblower outlet, a pair of vertically extending side partitions eachspaced from its side wall or" the housing and each abutting against theedges of the first and second vertical partitions and against the sidesof the horizon tally extending partition, at least one of the side wallshaving an opening therein providing fiuid communication with the inletof the blower forming an air inlet for air to be heated entering fromthe outer side of the side wall, the blower inlet fitting the opening toprevent fluid flow from the inner side of the side wall into the blower,and a partitioned plenum chamber under the housing, one part of theplenum chamber for cold air and a second part of the plenum chamher forwarm air, inlet and outlet means for both parts of the plenum chamber,the space inside the horizontal and vertical partitions and the outersurface of the blower outlet defining a combustion chamber with theinvolute surface of the blower extending across the top center of thecombustion chamber, the space within the housing outside the horizontaland vertical partitions leading from the outlet of the cold air part ofthe plenum chamber, the blower outlet communicating with the inlet ofthe warm air part of the plenum chamber so that air is passed betweenthe inner walls of the housing and the outer walls of the partitionsthence into the blower where it is further warmed by contact with theinner wall of the involute surface thence passed downwardly through theblower outlet to be superheated by the wall of the blower outlet formingpart of the combustion chamber and thence expelled into the inlet of thewarm air part plenum chamber.

2. In an air heating device, a housing, a combustion gas outlet adjacentthe top of the housing, a blower casing positioned within the housingand having an inlet, a warm air blower the blower casing, the blowercasing including an involute surface about the periphery of the blowerand a downwardly directed warm air blower outlet, a first verticallyextending partition positioned between one end wall of the housing andthe involute surface of the blower casing and spaced therebetween, ahorizontally extending partition having one and meeting the upper end ofthe first vertical partition and spaced between the top wall of thehousing and the top of the blower casing, a second vertically extendingpartition at its upper end meeting the other end of the horizontallyextending partition and at its lower end meeting the bottom of thehousing and spaced between the other end wall of the housing and theblower outlet, a pair or" ALL vertically extending side partitions eachspaced from its side wall of the housing and each abutting against theedges of the first and second vertical partitions and against the sidesof the horizontally extending partition, at least one of the side wallshaving an opening therein providing fluid communication with the inletof the blower forming an air inlet for air to be heated entering fromthe outer side of the side wall, the blower inlet fitting the opening toprevent fiuid flow from the inner side of the side wall into the blower,a generally U-shaped partition having its legs connected with the upperside portions of the vertically extending side partitions and positionedbetween the housing and a side partition about the opening therein andwith the legs thereof extending upwardly, the ends of such legs beingspaced from the top of the housing, and a partitioned plenum chamberunder the housing, one part of the plenum chamher for cold air and asecond part of the plenum chamber for warm air, inlet and outlet meansfor both parts of the plenum chamber, the space inside the horizontaland vertical partitions and the outer surface of the blower outletdefining a combustion chamber with the involute surface of the blowerextending across the top center of the combustion chamber, the spacewithin the housing outside the horizontal and vertical partitionsleading from the outlet of the cold air part of the plenum chamber, theblower outlet communicating with the inlet of the warm air part of theplenum chamber so that air is passed between the inner walls of thehousing and the outer walls of the partitions thence across the top ofthe horizontally extending partition over the U-shaped partition intothe blower where it is further warmed by contact with the inner wall ofthe involute surface thence passed downwardly through. the blower outletto be superheated by the wall of the blower outlet forming part thecombustion chamber and thence expelled into he inlet of the warm airpart plenum chamber.

3. In an air heating device, a housing, a combustion gas outlet adjacentthe top of the housing, a blower casing positioned within the housingand having an inlet, a warm air blower in the blower casing, the blowercasing including an involute surface about the periphery of the blowerand a downwardly directed warm air blower outlet, a first verticallyextending partition positioned between one end wall of the housing andthe involute surface of the blower casing and spaced therebetween, ahorizontally extending partition having one end meeting the upper end ofthe first vertical partition and spaced between the top wall of thehousing and the top of the blower casing, a second vertically extendingpartition at its upper end meeting the other end of the horizontallyextending partition and its lower end meeting the bottom of the housingand spaced between the other end wall of the housing and the bloweroutlet, a pair of vertically extending side partitions each spacedfl'ull its side wall of the housing and each abutting against the edgesof the first and second vertical partitions and against the sides of thehorizontally extending partition, at least one of the side walls havingan opening therein providing communication with the inlet of the blowerforming an air inlet for air to be heated entering from the outer sideof the sidewall, the blower inlet fitting the opening to prevent i'iuidfiow from the inner side of the sidewall into the blower, a generallyU-shaped partition having its legs connected with the upper sideportions or" the vertically side extending partitions and positionedbetween the housing and a side partition about the opening therein andwith the legs thereof extending upwardly,

the ends of such legs being spaced from the top of the housing, a bafilepartition interposed between the second vertical partition and theblower casing outlet terminating short of the housing bottom, an outletfor combustion gases communicating with the space between the secondvertical partition and the baiile partition to lead combustion gasesdownwardly and under the edge of the baffle to increase the length ofpass for the combustion gases about the blower outlet, and a partitionedplenum chamber under the housing, one part of the plenum chamber forcold air and a second part of the plenum chamber for warm air, inlet andoutlet means for both parts of the plenum chamber, the space inside thehorizontal and vertical partitions and the outer surface of the bloweroutlet defining a combustion chamber with the involute surface of theblower extending across the top center of the combustion chamber, thespace outside the horizontal and vertical partitions leading from theoutlet of the cold air part of the plenum chamber, the blower outletcommunicating with the inlet of the warm air part of the plenum chamberso that air is passed between the inner walls of the housing and theouter walls of the partitions thence across the top of the horizontallyextending partition over the U-shaped partition into the blower where itis further warmed by contact with the inner wall of the involute surfacethence passed downwardly through the blower outlet to be superheated bythe wall of the blower outlet forming part of the combustion chamber andthence expelled into the inlet of the warm air part plenum chamber.

4. In an air heating device, a housing, means providing a combustionchamber disposed within the housing, means to heat the combustionchamber, inlet and outlet means for the combustion chamber, an airheating blower having an involute casing disposed within the combustionchamber, the blower having its outlet directed downwardly, a plenumchamber under the housing, partition means to separate the plenumchamber into cold air and warm air parts, inlet and outlet means forboth parts of the plenum chamber, means providing a fluid passage fromthe outlet of the cold air part of the plenum chamber to the spacedefined between the inside of the housing and the outside of thecombustion chamber, and means providing an air passage through the wallof the combustion chamber into the blower inlet, the involute surface ofthe blower extending over the heating 10 means for the combustionchamber, the blower outlet extending downwardly at one side of thecombustion chamber to exhaust into the inlet of the warm air part of theplenum chamber.

5. In an air heating device, a housing, means providing a combustionchamber disposed within the housing, means to heat the combustionchamber, inlet and outlet means for the combustion chamber, an airheating blower having an involute casing disposed within the combustionchamber, the blower having its outlet directed downwardly, a plenumchamber under the housing, partition means to separate the plenumchamber into cold air and warm air parts, inlet and outlet means forboth parts of the plenum chamber, means providing a fluid passage fromthe outlet of the cold air part of the plenum chamber to the spacedefined between the inside of the housing and the outside of thecombustion chamber, means providing an air passage through the wall ofthe combustion chamber into the blower inlet, the involute surface ofthe blower extending over the heating means for the combustion chamber,the blower outlet extending downwardly at one side of the combustionchamber to exhaust into the inlet of the warm air part of the plenumchamber, and a bafiie member within the combustion chamber extendingdownwardly towards the bottom or" the housing and positioned adjacentthe blower outlet so that the path of the combustion gases is around thelower end of the baflle so that the outer surface of the blower outletis swept by the combustion gases as the gases pass out the combustionchamber outlet.

References Cited in the file of this patent UNITED STATES PATENTSGermany July 4, 1934

